Attachment 838276 Details for Bug 1044438 – Proposed patch

[patch] Proposed patch

0001-bz1044438-cifs-fix-offset-handling-in-cifs_iovec_wri.patch (text/plain), 2.21 KB, created by Sachin Prabhu on 2013-12-18 11:41:47 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Sachin Prabhu

Created: 2013-12-18 11:41:47 UTC

Size: 2.21 KB

patch

obsolete

>From d82e23bafdbe3d0b6a31db84a34af6df883618e0 Mon Sep 17 00:00:00 2001
>Date: Fri, 13 Apr 2012 17:16:59 -0400
>Subject: [RHEL6 PATCH] [bz1044438] cifs: fix offset handling in cifs_iovec_write
>
>A recent backport to the cifs module  for RHEL 6.5 introduced a
>function cifs_iovec_write() which is used by cache=none and
>cache=strict modes. This function contained a bug which incorrectly
>calculated the offsets resulting in an inability to do append
>writes in these cache modes. This was fixed upstream but unfortunately
>the fix wasn't backported together with the patches which introduced
>those cache modes to RHEL 6.5.
>
>The default cache mode in RHEL 6.5 is cache=loose which shouldn't be
>affected by this issue.
>
>Upstream commit: 3af9d8f227a31e25b3110ef175d105798fc147a6
>--
>In the recent update of the cifs_iovec_write code to use async writes,
>the handling of the file position was broken. That patch added a local
>"offset" variable to handle the offset, and then only updated the
>original "*poffset" before exiting.
>
>Unfortunately, it copied off the original offset from the beginning,
>instead of doing so after generic_write_checks had been called. Fix
>this by moving the initialization of "offset" after that in the
>function.
>
>Signed-off-by: Jeff Layton <jlayton@redhat.com>
>Signed-off-by: Steve French <sfrench@us.ibm.com>
>(cherry picked from commit 3af9d8f227a31e25b3110ef175d105798fc147a6)
>--
>
>Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
>---
> fs/cifs/file.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
>diff --git a/fs/cifs/file.c b/fs/cifs/file.c
>index e77b7c6..d1c4440 100644
>--- a/fs/cifs/file.c
>+++ b/fs/cifs/file.c
>@@ -1667,7 +1667,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
> 	unsigned long nr_pages, i;
> 	size_t copied, len, cur_len;
> 	ssize_t total_written = 0;
>-	loff_t offset = *poffset;
>+	loff_t offset;
> 	struct iov_iter it;
> 	struct cifsFileInfo *open_file;
> 	struct cifs_tcon *tcon;
>@@ -1689,6 +1689,7 @@ cifs_iovec_write(struct file *file, const struct iovec *iov,
> 	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
> 	open_file = file->private_data;
> 	tcon = tlink_tcon(open_file->tlink);
>+	offset = *poffset;
> 
> 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> 		pid = open_file->pid;
>-- 
>1.8.3.1
>

Actions: View | Diff

Attachments on bug 1044438: 838276